(a) Field of the Invention
The present invention relates to a trajectory correction apparatus, and more particularly, a trajectory correction apparatus for a dot sight, a scope or the like sight, which can improve an accuracy rate by correcting that a bullet hurled from a muzzle is affected by the gravity, the Coriolis' force caused by the rotation of the earth, the direction of wind, etc. and misses a target.
(b) Description of the Related Art
In the case of firearms, a trajectory is divided into an internal trajectory (or internal ballistics) from time when a bullet starts moving due to combustion and explosion of propulsive chemical substances in a gun barrel to time when the bullet leaves a muzzle or an open end of a gun (hereinafter, referred to as the “muzzle”), an external trajectory (or external ballistics) that the bullet coming out from the muzzle describes in the air, and a piercing trajectory that the bullet describes piercing the inside of the target after impact. According to difference in outward influences on the bullet, the trajectory is also divided into a vacuum trajectory affected by only the gravity of the earth without resistance of the air, and an air trajectory actually described in the air.
In the firearms, the external trajectory • the air trajectory are determined by external factors such as inertia based on initial velocity (direction and propulsive force) at a moment when the bullet leaves the muzzle, air resistance in the air, gravitation of the earth (the acceleration of gravity), Coriolis' force (deflecting force) caused by the rotation of the earth, etc.
In other words, the bullet leaving the muzzle is affected by not only the gravity with respect to a vertical direction to thereby fall down while forming a parabola, but also the Coriolis' force (deflecting force) with respect to a horizontal direction to thereby deflect the moving direction of the bullet rightward in the northern hemisphere. Further, the bullet leaving the muzzle deviates laterally from an aiming point on account of the direction and speed of wind while moving to the target.
Thus, in the case of a conventional personal gun, in order to hit a chest on a target board shaped like an upper half of a person's body, a part a little under a navel is aimed at a distance of 100 m, a navel part is aimed at a distance of 200 m, the chest is rightly aimed at a distance of 250 m, and so on by taking the foregoing trajectory into account. That is, the target is false aimed and shot in consideration of the trajectory. In result, the target is aimed not correctly but by a shooter's experience, and therefore correction considering the horizontal trajectory affected by the Coriolis' force (deflecting force) or an error caused by the direction of wind also depends on individual difference so as to false aim and shoot the target, thereby lowering an accuracy rate.